1. Field of the Invention
The present invention relates to a protection circuit board for a secondary battery. More specifically, the present invention relates to a test terminal formed on a protection circuit board used in a secondary battery.
2. Description of the Related Art
Portable electric/electronic devices, which have become more compact and lighter, such as cellular phones, notebook computers and camcorders are developed and produced. Thus, portable electric/electronic devices is usually provided with a battery pack so as to work in a place even where no power source is prepared. Considering the economic factor, the above battery pack recently adopts a chargeable/rechargeable secondary battery. Also, a secondary battery is expected to be applied in a hybrid car which requires high density energy and high power. It is now being studied, developed and produced.
A Ni—Cd battery, a battery, a Li battery and a Li-ion battery are representative secondary batteries.
Particularly, a Li-ion battery has an operating voltage of approximately 3 times higher than that of a Ni—Cd battery or a Ni-MH battery which are frequently used as portable electronic device power sources. Also, the Li-ion battery is widely used since the Li-ion battery has a high energy density per unit weight. The Li-ion battery usually employs a Li-based oxide as anode active material and a carbonic material as cathode active material. Generally, according to the kinds of electrolyte, secondary batteries are classified into liquid electrolyte batteries and high polymer electrolyte batteries. Batteries using a liquid electrolyte are named as Li-ion batteries while those using a high polymer electrolyte are named as Li-polymer batteries. Also, Li secondary batteries are being produced in various shapes. Representatively, there are cylinder-shaped, square-shaped and pouch-shaped batteries.
When the secondary batteries are charged or discharged, a voltage or a temperature, which is outputted from the secondary batteries, is measured. Since a protection circuit board, which administers the overall condition of the secondary batteries, is formed, it is possible to use the secondary batteries more stably. A printed circuit board pattern is formed on an electrically insulating substrate of the protection circuit board. A plurality of electric members and protection circuits are electrically connected to each other in the printed circuit board pattern. Also, on the protection circuit board, a charge-and-discharge terminal for charging/discharging a secondary battery and a test terminal for testing the normal operation state of the protection circuit board are electrically connected to the printed circuit board pattern. The charge-and-discharge terminal is not easily worn when it is connected to a battery connection terminal of a charger or an electronic appliance. In order to increase conductivity, the terminal surface is electrolytic plated. A connection part for the electrolytic plating is formed on the test terminal. A power source supplier for performing the electrolytic plating is connected to the connection part in order to apply a power source.
Since the contemporary connection part is formed on the periphery of a protection circuit board, however, static electricity tends to be introduced even after the electrolytic plating is finished. Also, since the connection part is electrically connected to a protection circuit, the static electricity, which has been introduced into the connection part, enters into the protection circuit. Due to the entrance of the static electrically, the internal integration circuit within the protection circuit is damaged.
In addition, when an electrolytic plating is performed on the contemporary test terminal or on the charge-and-discharge terminal, it takes approximately 8 hours. Due to this long process, the fabrication time of a protection circuit board is extended.
Furthermore, unlike the charge-and-discharge terminal, the surface of the contemporary test terminal has only a few numbers of contacts, so the use of an electrolytic plating method having superior hardness leads to an increase of fabrication costs.
Moreover, in addition to above problems, the color and luster of the test terminal, which is being exposed to the outside, should pursuit elegance for its graceful external appearance.